As a lead frame assembly in a semiconductor device, for example, Japanese Patent Application Laid-Open Publication No. 2003-209132 (Patent Document 1) discloses a structure in which a first plated surface composed of a metal containing nickel as a main component is formed in a half region on a lead-out-part side of a pad part of each lead terminal, and in which a second plated surface made of a metal containing silver as a main component is formed in a half region close to an edge part of a supporting plate of the pad part.
Also, In the lead frame assembly, for example, Japanese Patent Application Laid-Open Publication No. 2007-294530 (Patent Document 2) discloses a structure of a lead frame assembly in which a silver plated surface is formed on a distal-end surface of a pad part of five lead terminals, and in which a thin aluminum wire and a thin gold wire are connected to one of the lead terminals so that the thin aluminum wire is connected to a nickel plated surface and the thin gold wire is connected to the silver plated surface.
Also, in a semiconductor device provided with a semiconductor chip having a power MOSFET or a power bipolar transistor, for example, Japanese Patent Application Laid-Open Publication (Translation of PCT Application) No. 2000-503491 (Patent Document 3) discloses a structure in which the MOSFET or the bipolar transistor has two symmetrically-arranged output terminals on a surface of the semiconductor chip, and in which the output terminals are symmetrically connected to a circuit board via the same two bonding wires.
Also, in a semiconductor device, for example, Japanese Patent Application Laid-Open Publication No. H03-198356 (Patent Document 4) discloses a structure in which at least one of thin metal wires for connecting between a semiconductor element and an internal lead of a lead frame without a semiconductor-element-mounted part is thicker than the other thin metal wires and connects therebetween through the shortest path, and in which the semiconductor element is fixed to the internal lead.
Also, in a semiconductor device, for example, Japanese Utility-Model Application Laid-Open Publication No. H03-109818 (Patent Document 5) discloses a structure which the semiconductor device has a heat dissipating plate, a set of a plurality of leads, and a semiconductor pellet fixed on the heat dissipating plate, in which one lead among the plurality of leads is coupled to the heat dissipating plate, and in which an electrode on the semiconductor pellet and the other lead are electrically connected to each other by a wire.